Flashcards in Effect of SEM differences on confidence intervals Deck (12)

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1

## What does SEM measure?

### SEM is a measure of how much test scores are spread around a "true" score

2

## What is the APA definition of SEM?

### "The standard deviation of errors of measurement that is associated with the test scores for a specified group of test takers" (APA, 1985)

3

## What is the formula for SEM?

###
SEM=s√(1-r)

Where r = the reliability of the test

and s = the standard deviation of the test

4

## What is SEM usually accompanied by?

### A confidence interval (CI)

5

## What is a confidence interval?

### A range around the estimated "true" score

6

## What is the measurement unit for SEM?

###
The measurement unit is the same as the original test scores

E.g., if you're measuring in points, the SEM will be in points and if you're measuring in % the SEM will be in %

7

## What is the formula for the 95% CI?

### score ± (1.96*SEM)

8

## The magnitude of differences on the variables that comprise the SEM impact Cis as follows: At the highest level, the larger the overall value of the SEM, the X the range in your CI.

### The larger the overall value of the SEM, the greater the range in your CI.

9

##
In the SEM formula, there are two variables which we can change to impact our CIs, these are S, and r.

What happens to the CIs if we increase S?

### If we increase S then the range of the CIs increases in tandem

10

##
In the SEM formula, there are two variables which we can change to impact our CIs, these are S, and r.

What happens to the CIs if we decrease S?

### If we decrease S then the range of the CIs decreases in tandem

11

##
In the SEM formula, there are two variables which we can change to impact our CIs, these are S, and r.

What happens to the CIs if we increase r?

### If we increase r, then the range of the CIs decreases

12